/**
 * @class Ext.draw.Color
 * @extends Object
 *
 * Represents an RGB color and provides helper functions to get
 * color components in HSL color space.
 */
Ext.define('Ext.draw.Color', {

    colorToHexRe: /(.*?)rgb\((\d+),\s*(\d+),\s*(\d+)\)/,
    rgbRe: /\s*rgba?\s*\(\s*([0-9]+)\s*,\s*([0-9]+)\s*,\s*([0-9]+)\s*(,\s*[0-9\.]+\s*)?\)\s*/,
    hexRe: /\s*#([0-9a-fA-F][0-9a-fA-F]?)([0-9a-fA-F][0-9a-fA-F]?)([0-9a-fA-F][0-9a-fA-F]?)\s*/,

    /**
     * @cfg {Number} lightnessFactor
     *
     * The default factor to compute the lighter or darker color.
     */
    lightnessFactor: 0.2,

    /**
     * @constructor
     * @param {Number} red Red component (0..255)
     * @param {Number} green Green component (0..255)
     * @param {Number} blue Blue component (0..255)
     */
    // COMPAT Ext.util.Numbers -> Ext.Number
    constructor : function(red, green, blue) {
        var me = this,
            clamp = Ext.Number.constrain;
        me.r = clamp(red, 0, 255);
        me.g = clamp(green, 0, 255);
        me.b = clamp(blue, 0, 255);
    },

    /**
     * Get the red component of the color, in the range 0..255.
     * @return {Number}
     */
    getRed: function() {
        return this.r;
    },

    /**
     * Get the green component of the color, in the range 0..255.
     * @return {Number}
     */
    getGreen: function() {
        return this.g;
    },

    /**
     * Get the blue component of the color, in the range 0..255.
     * @return {Number}
     */
    getBlue: function() {
        return this.b;
    },

    /**
     * Get the RGB values.
     * @return {Array}
     */
    getRGB: function() {
        var me = this;
        return [me.r, me.g, me.b];
    },

    /**
     * Get the equivalent HSL components of the color.
     * @return {Array}
     */
    getHSL: function() {
        var me = this,
            r = me.r / 255,
            g = me.g / 255,
            b = me.b / 255,
            max = Math.max(r, g, b),
            min = Math.min(r, g, b),
            delta = max - min,
            h,
            s = 0,
            l = 0.5 * (max + min);

        // min==max means achromatic (hue is undefined)
        if (min != max) {
            s = (l < 0.5) ? delta / (max + min) : delta / (2 - max - min);
            if (r == max) {
                h = 60 * (g - b) / delta;
            } else if (g == max) {
                h = 120 + 60 * (b - r) / delta;
            } else {
                h = 240 + 60 * (r - g) / delta;
            }
            if (h < 0) {
                h += 360;
            }
            if (h >= 360) {
                h -= 360;
            }
        }
        return [h, s, l];
    },

    /**
     * Return a new color that is lighter than this color.
     * @param {Number} factor Lighter factor (0..1), default to 0.2
     * @return Ext.draw.Color
     */
    getLighter: function(factor) {
        var hsl = this.getHSL();
        factor = factor || this.lightnessFactor;
        // COMPAT Ext.util.Numbers -> Ext.Number
        hsl[2] = Ext.util.Numbers.constrain(hsl[2] + factor, 0, 1);
        return this.fromHSL(hsl[0], hsl[1], hsl[2]);
    },

    /**
     * Return a new color that is darker than this color.
     * @param {Number} factor Darker factor (0..1), default to 0.2
     * @return Ext.draw.Color
     */
    getDarker: function(factor) {
        factor = factor || this.lightnessFactor;
        return this.getLighter(-factor);
    },

    /**
     * Return the color in the hex format, i.e. '#rrggbb'.
     * @return {String}
     */
    toString: function() {
        var me = this,
            round = Math.round,
            r = round(me.r).toString(16),
            g = round(me.g).toString(16),
            b = round(me.b).toString(16);
        r = (r.length == 1) ? '0' + r : r;
        g = (g.length == 1) ? '0' + g : g;
        b = (b.length == 1) ? '0' + b : b;
        return ['#', r, g, b].join('');
    },

    /**
     * Convert a color to hexadecimal format.
     *
     * @param {String, Array} color The color value (i.e 'rgb(255, 255, 255)', 'color: #ffffff').
     * Can also be an Array, in this case the function handles the first member.
     * @returns {String} The color in hexadecimal format.
     */
    toHex: function(color) {
        if (Ext.isArray(color)) {
            color = color[0];
        }
        if (!Ext.isString(color)) {
            return '';
        }
        if (color.substr(0, 1) === '#') {
            return color;
        }
        var digits = this.colorToHexRe.exec(color);

        if (Ext.isArray(digits)) {
            var red = parseInt(digits[2], 10),
                green = parseInt(digits[3], 10),
                blue = parseInt(digits[4], 10),
                rgb = blue | (green << 8) | (red << 16);
            return digits[1] + '#' + ("000000" + rgb.toString(16)).slice(-6);
        }
        else {
            return '';
        }
    },

    /**
     * Parse the string and create a new color.
     *
     * Supported formats: '#rrggbb', '#rgb', and 'rgb(r,g,b)'.
     *
     * If the string is not recognized, an undefined will be returned instead.
     *
     * @param {String} str Color in string.
     * @returns Ext.draw.Color
     */
    fromString: function(str) {
        var values, r, g, b,
            parse = parseInt;

        if ((str.length == 4 || str.length == 7) && str.substr(0, 1) === '#') {
            values = str.match(this.hexRe);
            if (values) {
                r = parse(values[1], 16) >> 0;
                g = parse(values[2], 16) >> 0;
                b = parse(values[3], 16) >> 0;
                if (str.length == 4) {
                    r += (r * 16);
                    g += (g * 16);
                    b += (b * 16);
                }
            }
        }
        else {
            values = str.match(this.rgbRe);
            if (values) {
                r = values[1];
                g = values[2];
                b = values[3];
            } else {
                return Ext.draw.Color.fromName(str);
            }
        }

        return (typeof r == 'undefined') ? undefined : new Ext.draw.Color(r, g, b);
    },

    /**
     * Returns the gray value (0 to 255) of the color.
     *
     * The gray value is calculated using the formula r*0.3 + g*0.59 + b*0.11.
     *
     * @returns {Number}
     */
    getGrayscale: function() {
        // http://en.wikipedia.org/wiki/Grayscale#Converting_color_to_grayscale
        return this.r * 0.3 + this.g * 0.59 + this.b * 0.11;
    },

    /**
     * Create a new color based on the specified HSL values.
     *
     * @param {Number} h Hue component (0..359)
     * @param {Number} s Saturation component (0..1)
     * @param {Number} l Lightness component (0..1)
     * @returns Ext.draw.Color
     */
    fromHSL: function(h, s, l) {
        var C, X, m, rgb = [],
            abs = Math.abs,
            floor = Math.floor;

        if (s == 0 || h == null) {
            // achromatic
            rgb = [l, l, l];
        }
        else {
            // http://en.wikipedia.org/wiki/HSL_and_HSV#From_HSL
            // C is the chroma
            // X is the second largest component
            // m is the lightness adjustment
            h /= 60;
            C = s * (1 - abs(2 * l - 1));
            X = C * (1 - abs(h - 2 * floor(h / 2) - 1));
            m = l - C / 2;
            switch (floor(h)) {
                case 0:
                    rgb = [C, X, 0];
                    break;
                case 1:
                    rgb = [X, C, 0];
                    break;
                case 2:
                    rgb = [0, C, X];
                    break;
                case 3:
                    rgb = [0, X, C];
                    break;
                case 4:
                    rgb = [X, 0, C];
                    break;
                case 5:
                    rgb = [C, 0, X];
                    break;
            }
            rgb = [rgb[0] + m, rgb[1] + m, rgb[2] + m];
        }
        return new Ext.draw.Color(rgb[0] * 255, rgb[1] * 255, rgb[2] * 255);
    }
}, function() {
    var prototype = this.prototype;

    // TODO(zhangbei): do we have a better way to convert color names to rgb?
    this.addStatics({
        ColorList : {
            "aliceblue": "#f0f8ff", "antiquewhite": "#faebd7", "aqua": "#00ffff", "aquamarine": "#7fffd4", "azure": "#f0ffff",
            "beige": "#f5f5dc", "bisque": "#ffe4c4", "black": "#000000", "blanchedalmond": "#ffebcd", "blue": "#0000ff", "blueviolet": "#8a2be2", "brown": "#a52a2a", "burlywood": "#deb887",
            "cadetblue": "#5f9ea0", "chartreuse": "#7fff00", "chocolate": "#d2691e", "coral": "#ff7f50", "cornflowerblue": "#6495ed", "cornsilk": "#fff8dc", "crimson": "#dc143c", "cyan": "#00ffff",
            "darkblue": "#00008b", "darkcyan": "#008b8b", "darkgoldenrod": "#b8860b", "darkgray": "#a9a9a9", "darkgreen": "#006400", "darkkhaki": "#bdb76b", "darkmagenta": "#8b008b", "darkolivegreen": "#556b2f",
            "darkorange": "#ff8c00", "darkorchid": "#9932cc", "darkred": "#8b0000", "darksalmon": "#e9967a", "darkseagreen": "#8fbc8f", "darkslateblue": "#483d8b", "darkslategray": "#2f4f4f", "darkturquoise": "#00ced1",
            "darkviolet": "#9400d3", "deeppink": "#ff1493", "deepskyblue": "#00bfff", "dimgray": "#696969", "dodgerblue": "#1e90ff",
            "firebrick": "#b22222", "floralwhite": "#fffaf0", "forestgreen": "#228b22", "fuchsia": "#ff00ff",
            "gainsboro": "#dcdcdc", "ghostwhite": "#f8f8ff", "gold": "#ffd700", "goldenrod": "#daa520", "gray": "#808080", "green": "#008000", "greenyellow": "#adff2f",
            "honeydew": "#f0fff0", "hotpink": "#ff69b4",
            "indianred ": "#cd5c5c", "indigo ": "#4b0082", "ivory": "#fffff0", "khaki": "#f0e68c",
            "lavender": "#e6e6fa", "lavenderblush": "#fff0f5", "lawngreen": "#7cfc00", "lemonchiffon": "#fffacd", "lightblue": "#add8e6", "lightcoral": "#f08080", "lightcyan": "#e0ffff", "lightgoldenrodyellow": "#fafad2",
            "lightgrey": "#d3d3d3", "lightgreen": "#90ee90", "lightpink": "#ffb6c1", "lightsalmon": "#ffa07a", "lightseagreen": "#20b2aa", "lightskyblue": "#87cefa", "lightslategray": "#778899", "lightsteelblue": "#b0c4de",
            "lightyellow": "#ffffe0", "lime": "#00ff00", "limegreen": "#32cd32", "linen": "#faf0e6",
            "magenta": "#ff00ff", "maroon": "#800000", "mediumaquamarine": "#66cdaa", "mediumblue": "#0000cd", "mediumorchid": "#ba55d3", "mediumpurple": "#9370d8", "mediumseagreen": "#3cb371", "mediumslateblue": "#7b68ee",
            "mediumspringgreen": "#00fa9a", "mediumturquoise": "#48d1cc", "mediumvioletred": "#c71585", "midnightblue": "#191970", "mintcream": "#f5fffa", "mistyrose": "#ffe4e1", "moccasin": "#ffe4b5",
            "navajowhite": "#ffdead", "navy": "#000080",
            "oldlace": "#fdf5e6", "olive": "#808000", "olivedrab": "#6b8e23", "orange": "#ffa500", "orangered": "#ff4500", "orchid": "#da70d6",
            "palegoldenrod": "#eee8aa", "palegreen": "#98fb98", "paleturquoise": "#afeeee", "palevioletred": "#d87093", "papayawhip": "#ffefd5", "peachpuff": "#ffdab9", "peru": "#cd853f", "pink": "#ffc0cb", "plum": "#dda0dd", "powderblue": "#b0e0e6", "purple": "#800080",
            "red": "#ff0000", "rosybrown": "#bc8f8f", "royalblue": "#4169e1",
            "saddlebrown": "#8b4513", "salmon": "#fa8072", "sandybrown": "#f4a460", "seagreen": "#2e8b57", "seashell": "#fff5ee", "sienna": "#a0522d", "silver": "#c0c0c0", "skyblue": "#87ceeb", "slateblue": "#6a5acd", "slategray": "#708090", "snow": "#fffafa", "springgreen": "#00ff7f", "steelblue": "#4682b4",
            "tan": "#d2b48c", "teal": "#008080", "thistle": "#d8bfd8", "tomato": "#ff6347", "turquoise": "#40e0d0",
            "violet": "#ee82ee",
            "wheat": "#f5deb3", "white": "#ffffff", "whitesmoke": "#f5f5f5",
            "yellow": "#ffff00", "yellowgreen": "#9acd32"
        },
        fromHSL : function() {
            return prototype.fromHSL.apply(prototype, arguments);
        },
        fromString : function() {
            return prototype.fromString.apply(prototype, arguments);
        },
        fromName : function(name) {
            if (this.ColorList[name.toLowerCase()]){
                return this.fromString(this.ColorList[name.toLowerCase()]);
            } else {
                return null;
            }
        },
        toHex : function(color) {
            return prototype.toHex(color);
        }
    });
});
